National Library of Scotland Historic Maps APIHistorical Maps of Great Britain for use in mashups and ArcGIS Onlinehttps://nls.tileserver.com/https://maps.nls.uk/projects/api/index.htmlThis seamless historic map can be:embedded in your own websiteused for research purposesused as a backdrop for your own markers or geographic dataused to create derivative work (such as OpenStreetMap) from it.The mapping is based on out-of-copyright Ordnance Survey maps, dating from the 1920s to the 1940s.The map can be directly opened in a web browser by opening the Internet address: https://nls.tileserver.com/The map is ready for natural zooming and panning with finger pinching and dragging.How to embed the historic map in your websiteThe easiest way of embedding the historical map in your website is to copy < paste this HTML code into your website page. Simple embedding (try: hello.html):You can automatically position the historic map to open at a particular place or postal address by appending the name as a "q" parameter - for example: ?q=edinburgh Embedding with a zoom to a place (try: placename.html):You can automatically position the historic map to open at particular latitude and longitude coordinates: ?lat=51.5&lng=0&zoom=11. There are many ways of obtaining geographic coordinates. Embedding with a zoom to coordinates (try: coordinates.html):The map can also automatically detect the geographic location of the visitor to display the place where you are right now, with ?q=auto Embedding with a zoom to coordinates (try: auto.html):How to use the map in a mashupThe historic map can be used as a background map for your own data. You can place markers on top of it, or implement any functionality you want. We have prepared a simple to use JavaScript API to access to map from the popular APIs like Google Maps API, Microsoft Bing SDK or open-source OpenLayers or KHTML. To use our map in your mashups based on these tools you should include our API in your webpage: ... ...

This dataset comprises 2 collections of maps. The facsmile collection contains all the marginalia information from the original map as well as the map itself, while the georectified collection contains just the map with an associated index for locating them. Each collection comprises approximately 101 000 monochrome images at 6-inch (1:10560) scale. Each image is supplied in .tiff format with appropriate ArcView and MapInfo world files, and shows the topography for all areas of England, Wales and Scotland as either quarter or, in some cases, full sheets. The images will cover the approximate epochs 1880's, 1900's, 1910's, 1920's and 1930's, but note that coverage is not countrywide for each epoch. The data was purchased by BGS from Sitescope, who obtained it from three sources - Royal Geographical Society, Trinity College Dublin and the Ordnance Survey. The data is for internal use by BGS staff on projects, and is available via a customised application created for the network GDI enabling users to search for and load the maps of their choice. The dataset will have many uses across all the geoscientific disciplines across which BGS operates, and should be viewed as a valuable addition to the BGS archive. There has been a considerable amount of work done during 2005, 2006 and 2007 to improve the accuracy of the OS Historic Map Collection. All maps should now be located to +- 50m or better. This is the best that can be achieved cost effectively. There are a number of reasons why the maps are inaccurate. Firstly, the original maps are paper and many are over 100 years old. They have not been stored in perfect condition. The paper has become distorted to varying degrees over time. The maps were therefore not accurate before scanning. Secondly, different generations of maps will have used different surveying methods and different spatial referencing systems. The same geographical object will not necessarily be in the same spatial location on subsequent editions. Thirdly, we are discussing maps, not plans. There will be cartographic generalisations which will affect the spatial representation and location of geographic objects. Finally, the georectification was not done in BGS but by the company from whom we purchased the maps. The company no longer exists. We do not know the methodology used for georectification.

Colourful and easy to use, Bartholomew’s maps became a trademark series. The maps were popular and influential, especially for recreation, and the series sold well, particularly with cyclists and tourists. To begin with, Bartholomew printed their half-inch maps in Scotland as stand-alone sheets known as 'District Sheets' and by 1886 the whole of Scotland was covered. They then revised the maps into an ordered set of 29 sheets covering Scotland in a regular format. This was first published under the title Bartholomew’s Reduced Ordnance Survey of Scotland. The half-inch maps of Scotland formed the principal content for Bartholomew's Survey Atlas of Scotland published in 1895. Bartholomew then moved south of the Border to the more lucrative but competitive market in England and Wales, whilst continuing to revise the Scottish sheets. The first complete coverage of Great Britain at the half-inch scale was achieved by 1903, and this is the layer shown here.The half-inch maps were distinctive for using different layers of colour to represent landscape relief. A subtle and innovative gradation of colour bands were employed for land at different heights. Lighter greens were used for low ground closest to sea-level, darker greens and browns for higher ground, with white used for mountain tops. Whilst layer colouring had been developed in Germany from the 1860s, Bartholomew's development of it was both innovative and influential. John Bartholomew junior (1831-1893) first used the firm's trademark layer colouring in Baddeley’s Thorough Guide to the English Lake District (1880). His son, John George Bartholomew (1860-1920), later went on to refine the style. You can see Bartholomew’s continued experimentation with layer colour palettes in the Cairngorms layer colour explorer ( http://geo.nls.uk/maps/bartholomew/layers/ )

Bartholomew based their half-inch maps on more detailed Ordnance Survey mapping at one-inch to the mile (1:63,360). The firm had published 'Reduced Ordnance Maps' of Scotland, England and Wales at this scale from the 1890s. These maps were progressively revised and updated with new information. Usually Bartholomew made revisions the sheets right up to the time of publication, so the date of publication is the best guide to the approximate date of the features shown on the map. You can view the dates of publication for the series at:

● Scotland: https://maps.nls.uk/series/bart_half_scotland.html

● England and Wales: https://maps.nls.uk/series/bart_half_england.html

This dataset contains summary data regarding historical (1930s-40s) land use and land-use change between 1930s and 2007 according to broad land-use categories. Data provided are summary values at the 10-km grid square 'hectad' level of the British National Grid, specifying the proportion and proportion of change in broad land-use categories.

Historical data are based on the first Land Utilisation Survey of Great Britain (Stamp 1931). For England and Wales, digitisation of the historical maps contains information supplied by Natural England, based on methods developed by Baily et al. (2011). For Scotland, map images were digitised using the R package HistMapR (Auffret et al. 2017). Both methods involve processing and classifying images based on the colour of the historical land-use map categories. Classified maps were then resampled to the 25m resolution of the modern UK Land Cover Map 2007 (Morton et al. 2011), and both historical and modern land-use categories were adjusted to produce broad categories of equivalent land use: Arable, Grassland, Urban, Woodland, Agriculturally-Improved Grassland and Surface Water. In Scotland, surface water from a modern map is used for the historical time period due to issues in classifying this category. Pixels within a 75m buffer of the modern road network were removed due to the disproportionate size of roads shown in the historical maps, and pixels falling into some coastal land-use categories in the modern maps were removed due to a lack of equivalent in the historical maps. The proportions of remaining pixels within each hectad, and the change in the proportion over time was then calculated. Full details of data creation and processing can be found in Suggitt et al. (2023), and more information on the data files can be found in the readme.

The extent of the data files: GB_LandUseChange_Data.csv - table containing summary data, 2802 rows and 15 columns GB_LandUseChange_LowlandGrasslandChange.csv - table containing data on lowland grassland change, 2802 rows and 10 columns

The file GB_LandUseChange_Raster.tif is a GeoTIFF file primarily intended to be used with the R script. It can also be opened using other GIS software.

If R is installed with required packages (see sessionInfo.txt), the file Rplots.pdf can be generated running: Rscript GB_LandUseChange_Code.R

References:

Auffret, A.G., Kimberley, A., Plue, J., Skånes, H., Jakobsson, S., Waldén, E., Wennbom, M., Wood, H., Bullock, J.M., Cousins, S.A.O., Gartz, M., Hooftman, D.A.P., Tränk, L., 2017, HistMapR: Rapid digitization of historical land-use maps in R, Methods in Ecology and Evolution 8: 1453-1457. https://doi.org/10.1111/2041-210X.12788

Baily, B., Riley, M., Aucott, P. & Southall, H., 2011, Extracting digital data from the First Land Utilisation Survey of Great Britain – Methods, issues and potential, Applied Geography 31: 959-968. https://doi.org/10.1016/j.apgeog.2010.12.007

Morton, D., Rowland, C., Wood, C., Meek, L., Marston, C., Smith, G., Wadsworth, R., Simpson, I.C., 2011, Final Report for LCM2007 – the new UK Land Cover Map, Centre for Ecology & Hydrology, Wallingford, UK. http://nora.nerc.ac.uk/id/eprint/14854

Stamp, D.L., 1931, The Land Utilisation Survey of Britain. Geographical Journal 78: 40-47. https://doi.org/10.2307/1784994

Suggitt, A.J., Wheatley, C.J., Aucott, P., Beale, C.M., Fox, R., Hill, J.K., Isaac, N.J.B., Martay, B., Southall, H., Thomas, C.D., Walker, K.J., Auffret, A.G., 2023, Linking climate warming and land conversion to species’ range changes across Great Britain, Nature Communications, https://doi.org/10.1038/s41467-023-42475-0

Georeferenced map of 'Plan of Edinburgh and Leith, from the Survey Atlas of Scotland' By J.G. Bartholomew (1912) as part of the Visualising Urban Geographies project- view other versions of the map at http://geo.nls.uk/urbhist/resources_maps.html. Scanned map. This dataset was first accessioned in the EDINA ShareGeo Open repository on 2011-05-31 and migrated to Edinburgh DataShare on 2017-02-21.

The Historic Flood Map is a GIS layer showing the maximum extent of individual Recorded Flood Outlines from river, the sea and groundwater springs that meet a set criteria. It shows areas of land that have previously been subject to flooding in England. This excludes flooding from surface water, except in areas where it is impossible to determine whether the source is fluvial or surface water but the dominant source is fluvial.

The majority of records began in 1946 when predecessor bodies to the Environment Agency started collecting detailed information about flooding incidents, although we hold limited details about flooding incidents prior to this date.

If an area is not covered by the Historic Flood Map it does not mean that the area has never flooded, only that we do not currently have records of flooding in this area that meet the criteria for inclusion. It is also possible that the pattern of flooding in this area has changed and that this area would now flood or not flood under different circumstances. Outlines that don’t meet this criteria are stored in the Recorded Flood Outlines dataset.

The Historic Flood Map takes into account the presence of defences, structures, and other infrastructure where they existed at the time of flooding. It will include flood extents that may have been affected by overtopping, breaches or blockages.

Flooding is shown to the land and does not necessarily indicate that properties were flooded internally.

Georeferenced map of 'he City of Edinburgh and its environs' By Robert Kirkwood (1804) as part of the Visualising Urban Geographies project- view other versions of the map at http://geo.nls.uk/urbhist/resources_maps.html. Scanned map. This dataset was first accessioned in the EDINA ShareGeo Open repository on 2011-05-31 and migrated to Edinburgh DataShare on 2017-02-21.

About this layerThe Land Use Database held by the Northern Ireland Environment Agency (NIEA) provides a record of approximately 14,000 sites that have had previous industrial land use(s).What can you do with the layer?Visualisation: This layer can be used for visualisation online in web maps and in ArcGIS Pro.Analysis: This layer can be used in dashboards.Download: The data is downloadable.This layer is part of the Living Atlas of the World that provides access to thousands of beautiful and authoritative layers, web maps and apps.

This map of Medieval England contains a wealth of historical information and sites as well as beautiful illustrations. Published in October 1979 as a companion to the modern map "British Isles".>> Order print map <<

High resolution scanned images of Ordnance Survey maps from 1932 and 1933 in .tif file format, and corresponding .pdf format versions of these.These show parts of Salford, including the former docks, and the western side of Manchester city centre. A0 sized poster prints of these maps were used as part of the Undiscovered Salford display in the Community Science Showcase at Manchester Science Festival's GameLab event. The event took place on 20/21 October 2018 at the University of Salford's MediaCityUK campus.Original files kindly provided by the Salford Local History Library from their archives held at the Salford Art Gallery & Museum.OS Copyright expires 50 years from the date of publication, hence these maps are copyright free.

Roads in central southern England c.1675, constructed from John Ogilby's strip maps.The .kml file gives a crude preview; please download the shapefiles for discrimination between major routes, minor routes, and speculative spurs.

The BGS database of geological maps is an index into BGS holdings of modern and historical published geological maps, geological standards and field slips, and also contains a range of other map series, including geophysical maps, geochemical maps, hydrogeological maps, thematic maps and other small-scale miscellaneous non-series maps. Historical vertical and horizontal sections, as well as indices to colours, are also included. The database comprises map metadata, including the title, theme, survey and revision years, publication years, mapped geological theme, base material, map function, colouration, approval status and the spatial extent of each map sheet. An accompanying file store contains high-resolution JPEG2000 scans for delivery, as well as various digital master and delivery formats. For a small number of maps, no scan exists. In total, the database contains over 240,000 scans of over 130,000 maps and field slips. The majority of the maps in the database cover Great Britain, but other regions are also represented, including a historical series of 1-inch maps of Ireland, 6-inch maps of the Isle of Man, 1:25 000 scale maps of the Channel Islands, and various overseas maps. The database contains a record of all geological maps produced by the British Geological Survey and its predecessors since the commencement of systematic geological mapping in the 1830s. The BGS Maps Database is mostly an archive of previous BGS maps, and is not the same as the latest BGS digital mapping. The maps within the database may differ significantly from BGS digital vector mapping. Further information about BGS digital vector mapping is available on the BGS website, under 'BGS Datasets'. The database has evolved over time, originally being a series of discrete databases. These databases have now been aggregated into a single dataset. BGS published maps, as well as 1:10 560 and 1:10 000 large-scale geological maps of England and Wales, and Scotland, are available through the BGS Maps Portal. Field slips and some thematic maps are not included on the BGS Maps Portal. The information about a map is normally a transcription from the map itself. Sometimes key information such as the title may not be actually printed on the map. Where this is the case the information is supplied in square brackets, e.g. [Kirk Maiden]. Information in square brackets means the information is supplied by the cataloguer and is not transcribed from the item.

This dataset contains a sample of 10,000 (3.5%) out of a total of 285,846 text sequences extracted from the 1891–1896 Map of London by the Ordnance Survey (OS).

The methodology used for the automated recognition, linking, and sequencing of the text is detailed in the article Recognizing and Sequencing Multi-word Texts in Maps Using an Attentive Pointer by M. Zou et al., 2025.

Description of the content

The map is drawn at a scale of five-feet to the mile (c.a. 1:1,056). The text on the map is an invaluable source of information about the Greater London in the late Victorian period. It includes the names of streets, squares, parks, watercourses and even some estates ('Poplars', 'The Grange', 'Arbutus Lodge'). In addition, the map contains many details of the function of buildings and economic activity, such as factories ('Sweet Factory', 'Crown Linoleum Works', 'Imperial Flour Mills', 'Lion Brewery'), warehouses or commercial infrastructure ('Warehouse', 'Jamaica Wharf', 'Rag Store'), offices ('Offices'), etc. The map also mentions public buildings such as schools ('School Boys, Girls & Infants', 'Sunday School'), hospitals or clinics ('St. Saviour's Union Infirmary', 'Beulah Spa Hydropathic Establishment', 'South Western Fever Hospital'), railway stations ('Clapham Station'), post offices, banks, police stations, etc. Other social venues are also mentioned, such as public houses, i.e. pubs ('P.H.'), clubs, casinos, and recreational areas (e.g. 'Cricket Ground'). Special attention is given to churches, with a regular count of the number of seats (e.g. 'Baptist Chapel Seats for 600').

In addition, the map provides details that can be of great interest in the study of everyday life in London at the end of the 19th century. For example, there are numerous mentions of 'Stables', 'Drinking Fountain'[s] (or simply 'Fn.') or 'Urinal'[s]. Fire protection infrastructure is highlighted, e.g. fire plugs ('F.P.') and fire alarms ('F.A.'). The map also includes information on elevation (e.g. '11·6') and flood levels (e.g. 'High Water Mark of Ordinary Tides').

A list of abbreviations used in the Ordnance Survey maps, created by Richard Oliver [1], is made available by the National Library of Scotland (link).

Organization of the data

The data in 10k_text_london_OS_1890s.geojson is organized as a regular geojson file.

Example structure

{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"geometry": {
"type": "MultiPolygon",
"coordinates": [[[ [x1, y1], [x2, y2], ...]]]
},
"properties": {
"label": "Oxford Circus",
}
},

... # Further text sequences


]
}

Image documents

The original map document consists of 729 separate sheets, digitized, georeferenced, and served as geographic tiles by the National Library of Scotland [2].

Descriptive statistics

Total Number of text sequences: 285,846
Sample size: 10,000
Total Area covered: 450 square km

Use and Citation

For any mention of this dataset, please cite :

@misc{text_london_OS_1890s,
author = {Zou, Mengjie and Petitpierre, R{\'{e}}mi and di Lenardo, Isabella},
title = {{London 1890s Ordnance Survey Text Layer}},
year = {2025},
publisher = {Zenodo},
url = {https://doi.org/10.5281/zenodo.14982946}}

@article{recognizing_sequencing_2025,
author = {Zou, Mengjie and Dai, Tianhao and Petitpierre, R{\'{e}}mi and Vaienti, Beatrice and di Lenardo, Isabella},
title = {{Recognizing and Sequencing Multi-word Texts in Maps Using an Attentive Pointer}},
year = {2025}}

Corresponding author

Rémi PETITPIERRE - remi.petitpierre@epfl.ch - ORCID - Github - Scholar - ResearchGate

License

This project is licensed under the CC BY 4.0 License.

Liability

We do not assume any liability for the use of this dataset.

References

1. Oliver R. (2013). Ordnance Survey maps: A concise guide for historians. The Charles Close Society. London, UK. 3rd Ed. 320 pages
2. Ordnance Survey, London, five feet to the mile, 1893-1896 (1896), https://maps.nls.uk/os/townplans-england/london-1056-1890s.html, digitized by the National Library of Scotland (NLS)

Georeferenced map of 'Old and New Town of Edinburgh and Leith with the proposed docks' By John Ainslie (1804) as part of the Visualising Urban Geographies project- view other versions of the map at http://geo.nls.uk/urbhist/resources_maps.html. Scanned map. This dataset was first accessioned in the EDINA ShareGeo Open repository on 2011-05-31 and migrated to Edinburgh DataShare on 2017-02-21.

The Historic Environment Opportunity Map for New Woodland dataset identifies areas in England that may be suitable for new woodland, based solely on available Historic Environment data. The dataset categorises land by different opportunity ratings to reflect the potential suitability of land for woodland creation while acknowledging areas of uncertainty due to data availability.

The purpose of this dataset is to guide landowners, planners, and decision-makers in considering woodland creation from a historic environment perspective. It should be noted that this dataset only considers the Historic Environment and therefore the opportunity ratings do not guarantee or preclude approval for woodland creation proposals.

As any forestry proposal could have the potential to affect the Historic Environment you should contact your local historic environment service. The local historic environment service can provide further data to support woodland creation proposals.

NHLE is the official, up to date register of all nationally protected historic buildings and sites in England.

SHINE is a single, nationally consistent dataset of non-designated historic and archaeological features from across England that could benefit from land management schemes.

The opportunity ratings are as defined:

· Favourable - Areas deemed suitable for new woodland on consideration of available Historic Environment data.

· Neutral - Areas deemed neither favourable nor unfavourable for new woodland on consideration of available Historic Environment data. Proposals in these areas will require additional consideration of the Historic Environment on a case-by-case basis.

· Unclassified - Areas, where SHINE data has been supplied, with no assigned opportunity rating. This illustrates a current absence of recorded data from a Historic Environment perspective. However, as SHINE data is included in the dataset for this area, a degree of confidence may be inferred when considering the absence of historic environment features.

· Unclassified (No SHINE supplied) - Areas, where SHINE data has not been supplied, with no assigned opportunity rating. This illustrates a current absence of recorded data from a Historic Environment perspective.

· Unsuitable - Areas deemed unsuitable for new woodland on consideration of available Historic Environment data.

Unclassified areas may be suitable or unsuitable for new woodland. To better understand these areas, contact the local historic environment service in accordance with the UKFS and Historic Environment Guidance for Forestry in England - GOV.UK

The datasets included in each opportunity rating are as follows:

Favourable

· Lost Historic Woodlands (ArchAI/Forestry Commission) – An A.I. dataset that identifies areas of woodland depicted on early 20th Century Ordnance Survey mapping which have since been lost.

Neutral

· Historic Parklands (Zulu Ecosystems) – an A.I. dataset that identifies areas of parkland depicted on early 20th Century Ordnance Survey mapping.

· World Heritage Site Core data (Historic England) – Core areas of World Heritage Sites, as designated by UNESCO.

· World Heritage Site Buffer (Historic England) – Buffer zones surrounding World Heritage Sites, as designated by UNESCO.

· Ridge and Furrow (Low) (ArchAI) – an A.I. dataset that identifies areas of less well-preserved historic ridge and furrow derived from LiDAR data.

Unclassified

· HER Boundaries (SHINE supplied) – Geographic areas covered by local historic environment services, where SHINE data has been supplied to the Forestry Commission.

· HER Boundaries (No SHINE supplied) - Geographic areas covered by local historic environment services where SHINE data has not been supplied to the Forestry Commission.

Unsuitable

· Historic Landscape Characterisation (HLC) (local historic environment services) – regional datasets that provide information on the historic character of the landscape.

· Scheduled Monuments (Historic England) – Protected archaeological sites of national importance.

· Scheduled Monuments Buffer – A 20 metre buffer surrounding Scheduled Monuments in-line with UKFS.

· Selected Heritage Inventory for Natural England (SHINE)(local historic environment services) – National dataset of non-designated heritage assets.

· Registered Parks and Gardens (Historic England) – Parks and Gardens designated as being of national significance.

· Registered Battlefields (Historic England) – Battlefields designated as being of national significance.

· Ridge and Furrow (High) (ArchAI) – an A.I. dataset that identifies areas of well-preserved historic ridge and furrow derived from LiDAR data.

Historical Map Data is owned and supplied by Landmark Information Group and Ordnance Survey (OS) and supplied to Natural Resource Wales (NRW) via an OS licence. Landmark Information Group Limited holds the most extensive digital collection of historical Ordnance Survey mapping of Great Britain. This has been taken from Ordnance Survey’s archive of Town Plans, County Series and National Grid mapping covering the period from 1841 to 1996. Historical mapping provides a unique insight into our past and is a fascinating journey through history in itself. Particularly when displayed with contemporary mapping or aerial photography. Historical Map Data is available for different time periods, referred to as epochs. Epoch 1: the first County Series survey; published dates 1843 to 1893 Epoch 2: the first County Series revision; published dates 1891 to 1912 Epoch 3: the second County Series revision; published dates 1904 to 1939 Epoch 4: the third County Series revision; published dates 1919 to 1939

These geolocated datasets derive from annotations of Christopher Saxton's County Maps of England & Wales, annotations of published volumes of John Leland's Itineraries in Wales, and annotations of Wenceslaus Hollar's vignettes intended for publication in Britannia.

Please see the GitHub repository for details of the sources used and visualisation of their geographic scope.

Abstract copyright UK Data Service and data collection copyright owner. These digital boundaries were created by the Great Britain Historical GIS Project and form part of the Great Britain Historical Database, which contains a wide range of geographically-located statistics, selected to trace the emergence of the north-south divide in Britain and to provide a synoptic view of the human geography of Britain, generally at sub-county scales. They represent the boundaries of Registration Counties in England and Wales as in use at the date of each Census of Population between 1851 and 1911, 1911 being the last census to report extensively on these units. Main Topics: These digital boundaries can be used to map economic, social and demograohic statistics from the Censuses of Population, 1851 to 1911, the Registrar-General's reports from the same period, and other relevant statistical sources. They can also be used as reference maps for these administrative units, which often differ substantially from both Ancient Counties and 20th century Administrative Counties. The boundary data contain the same numerical identifiers as are included in the GBHDB transcriptions of census and vital registration statistics for Registration Counties, making statistical mapping very straightforward.

The 1885 UK parliamentary constituencies for Ireland were re-created in 2017 as part of a conference paper delivered at the Southern Irish Loyalism in Context conference at Maynooth University. The intial map only included the territory of the Irish Free State and was created by Martin Charlton and Jack Kavanagh. The remaining six counties of Ulster were completed by Eoin McLaughlin in 2018-19, the combined result is a GIS map of all the parliamentary constituecies across the island of Ireland for the period 1885-1918. The map is available in both ESRI Shapefile format and as a GeoPackage (GPKG). The methodology for creating the constituencies is outlined in detail below.

Methodology

A map showing the outlines of the 1855 – 1918 Constituency boundaries can be found on page 401 of Parliamentary Elections in Ireland, 1801-1922 (Dublin, 1978) by Brian Walker. This forms the basis for the creation of a set of digital boundaries which can then be used in a GIS. The general workflow involves allocating an 1885 Constituency identifier to each of the 309 Electoral Divisions present in the boundaries made available for the 2011 Census of Population data release by CSO. The ED boundaries are available in ‘shapefile’ format (a de facto standard for spatial data transfer). Once a Constituency identifier has been given to each ED, the GIS operation known as ‘dissolve’ is used to remove the boundaries between EDs in the same Constituency. To begin with Walker’s map was scanned at 1200 dots per inch in JPEG form. A scanned map cannot be linked to other spatial data without undergoing a process known as georeferencing. The CSO boundaries are available with spatial coordinates in the Irish National Grid system. The goal of georeferencing is to produce a rectified version of the map together with a world file. Rectification refers to the process of recomputing the pixel positions in the scanned map so that they are oriented with the ING coordinate system; the world file contains the extent in both the east-west and north-south directions of each pixel (in metres) and the coordinates of the most north-westerly pixel in the rectified image.

Georeferencing involves the identification of Ground Control Points – these are locations on the scanned map for which the spatial coordinates in ING are known. The Georeferencing option in ArcGIS 10.4 makes this a reasonably pain free task. For this map 36 GCPs were required for a local spline transformation. The Redistribution of Seats Act 1885 provides the legal basis for the constituencies to be used for future elections in England, Wales, Scotland and Ireland. Part III of the Seventh Schedule of the Act defines the Constituencies in terms of Baronies, Parishes (and part Parishes) and Townlands for Ireland. Part III of the Sixth Schedule provides definitions for the Boroughs of Belfast and Dublin.

The CSO boundary collection also includes a shapefile of Barony boundaries. This makes it possible code a barony in two ways: (i) allocated completely to a Division or (ii) split between two Divisions. For the first type, the code is just the division name, and for the second the code includes both (or more) division names. Allocation of these names to the data in the ED shapefile is accomplished by a spatial join operation. Recoding the areas in the split Baronies is done interactively using the GIS software’s editing option. EDs or groups of EDs can be selected on the screen, and the correct Division code updated in the attribute table. There are a handful of cases where an ED is split between divisions, so a simple ‘majority’ rule was used for the allocation. As the maps are to be used at mainly for displaying data at the national level, a misallocation is unlikely to be noticed. The final set of boundaries was created using the dissolve operation mentioned earlier. There were a dozen ED that had initially escaped being allocated a code, but these were quickly updated. Similarly, a few of the EDs in the split divisions had been overlooked; again updating was painless. This meant that the dissolve had to be run a few more times before all the errors have been corrected.

For the Northern Ireland districts, a slightly different methodology was deployed which involved linking parishes and townlands along side baronies, using open data sources from the OSM Townlands.ie project and OpenData NI.

United Kingdom Exports of maps, hydrographic or similar charts (printed) to United States was US$19.82 Million during 2024, according to the United Nations COMTRADE database on international trade. United Kingdom Exports of maps, hydrographic or similar charts (printed) to United States - data, historical chart and statistics - was last updated on August of 2025.